Relationship between Electronic and Geometric Structures of the O/Cu(001) System

The electronic structure of the $(2\sqrt{2}\times\sqrt{2})R45^{\circ}$ O/Cu(001) system has been calculated using locally self-consistent, real space multiple scattering technique based on first principles. Oxygen atoms are found to perturb differentially the long-range Madelung potentials, and hence the local electronic subbands at neighboring Cu sites. As a result the hybridization of the oxygen electronic states with those of its neighbors leads to bonding of varying ionic and covalent mix. Comparison of results with those for the c(2x2) overlayer shows that the perturbation is much stronger and the Coulomb lattice energy much higher for it than for the $(2\sqrt{2}\times\sqrt{2})R45^{\circ}$ phase. The main driving force for the 0.5ML oxygen surface structure formation on Cu(001) is thus the long-range Coulomb interaction which also controls the charge transfer and chemical binding in the system.Comment: 17 pages, 8 figure

Classical and quantum geometrodynamics of 2d vacuum dilatonic black holes

We perform a canonical analysis of the system of 2d vacuum dilatonic black holes. Our basic variables are closely tied to the spacetime geometry and we do not make the field redefinitions which have been made by other authors. We present a careful discssion of asymptotics in this canonical formalism. Canonical transformations are made to variables which (on shell) have a clear spacetime significance. We are able to deduce the location of the horizon on the spatial slice (on shell) from the vanishing of a combination of canonical data. The constraints dramatically simplify in terms of the new canonical variables and quantization is easy. The physical interpretation of the variable conjugate to the ADM mass is clarified. This work closely parallels that done by Kucha{\v r} for the vacuum Schwarzschild black holes and is a starting point for a similar analysis, now in progress, for the case of a massless scalar field conformally coupled to a 2d dilatonic black hole.Comment: 21 pages, latex fil

Doping induced inhomogeneity in high-Tc superconductors

Doping and disorder are inseparable in the superconducting cuprates. Assuming the simplest possible disordered doping, we construct a semiphenomenological model and analyze its experimental consequences. Among the affected experimental quantities are the ARPES spectra and thermodynamic properties. From our model we make a prediction for the width of the local superconducting gap distribution with the only experimentally unknown parameter being the superconducting correlation length. Thus, our model provides a direct way of determining the superconducting correlation length from a known experimental gap distribution.Comment: 5 pages, 3 eps figures. Expanded version of talk presented by AVB at the ISS 2000, Oct 14-16, Tokyo, Japa

PRODUCTION OF BETALAINS FROM HAIRY ROOT CULTURE OF BETA VULGARIS AND ITS USE IN PARACETAMOL SYRUP AS A NATURAL COLOURANT

Objective: The present study was aimed to extract betalains from hairy root culture of Beta vulgaris and its use in pharmaceutical formulations as a colorant. Methods: Hairy roots were initiated using different strains of Agrobacterium rhizogenes such as A.2/83, A.20/83, A.4, and LMG 150; LMG 150 was found to initiate a large number of hairy roots, and betalain content was estimated. Paracetamol syrup was prepared using extracted betalains as a colorant at different concentrations of 10 and 30 mg/150 ml. Stability studies were carried out at a different temperatures such as 25°C, 30°C, and 40°C) and light (dark, 1000 and 2000 lux) for 45 days. Results: In case of a concentration of 10 mg/150 ml syrup, the effects of temperature such as 25°C, 30°C, and 40°C and dark condition on the degradation of betalains were found to be 48%, 88%, and 100% in 45 days, respectively. The effects of temperature such as 25°C, 30°C, and 40°C at light 1000 lux on degradations of betalains were found to be 81% and 98% at 25°C and 30°C in 45 days, respectively, and 100% at 40°C in 30 days and at 2000 lux were found to be 100% at 25°C and 30°C in 30 days and 100% at 40°C in 10 days. The similar levels of degradation rate were observed with a concentration of 30 mg/150 ml. Conclusion: Experimental data demonstrated that formulation with betalains exhibited better stability at the dark condition and lower temperature

Dirac Quantization of Parametrized Field Theory

Parametrized field theory (PFT) is free field theory on flat spacetime in a diffeomorphism invariant disguise. It describes field evolution on arbitrary foliations of the flat spacetime instead of only the usual flat ones, by treating the `embedding variables' which describe the foliation as dynamical variables to be varied in the action in addition to the scalar field. A formal Dirac quantization turns the constraints of PFT into functional Schrodinger equations which describe evolution of quantum states from an arbitrary Cauchy slice to an infinitesimally nearby one.This formal Schrodinger picture- based quantization is unitarily equivalent to the standard Heisenberg picture based Fock quantization of the free scalar field if scalar field evolution along arbitrary foliations is unitarily implemented on the Fock space. Torre and Varadarajan (TV) showed that for generic foliations emanating from a flat initial slice in spacetimes of dimension greater than 2, evolution is not unitarily implemented, thus implying an obstruction to Dirac quantization. We construct a Dirac quantization of PFT,unitarily equivalent to the standard Fock quantization, using techniques from Loop Quantum Gravity (LQG) which are powerful enough to super-cede the no- go implications of the TV results. The key features of our quantization include an LQG type representation for the embedding variables, embedding dependent Fock spaces for the scalar field, an anomaly free representation of (a generalization of) the finite transformations generated by the constraints and group averaging techniques. The difference between 2 and higher dimensions is that in the latter, only finite gauge transformations are defined in the quantum theory, not the infinitesimal ones.Comment: 33 page

2008 Abstracts Collection -- IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science

This volume contains the proceedings of the 28th international conference on the Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2008), organized under the auspices of the Indian Association for Research in Computing Science (IARCS)

PHYTOCHEMICAL SCREENING AND COMPARATIVE GC–MS ANALYSIS OF BIOACTIVE COMPOUNDS PRESENT IN METHANOLIC LEAF AND LATEX EXTRACT Calotropis gigantea (L)

Medicinal plants are considered as important source of promising bioactive compounds. Calotropis gigantea is a traditional medicinal plant which is known to have biochemical constituents with potential medicinal properties. Qualitative analysis showed the presence of alkaloids, terpenoids, saponins, tannins and cardiac glycosides and absence of flavonoids in ethanolic extract of C. gigantea, while the chloroform leaf extract showed absence of flavonoids and cardiac glycosides. Bioactive compounds since leaf and latex of C. gigantea utilized GC-MS and activity investigation. The GC-MS investigation uncovered the presence of complete 46 bioactive mixes (24 from leaves and 22 from latex) with significant movement. The majority of the mixes were discovered to be comparable in both leaf and latex, however little variety was likewise seen in their synthetic profile. The concoction mixes saw in just latex were 1-[(T-butyl) dimethyl silyl thin] butane, 1-Hexadecyne, Hexadecane, L-Glutamic corrosive, Phenol-3-isoproxy-5-methyl, Trocosane and Z-1,6-Tridecadiene. Mixes distinguished uniquely from the leaves were Azulene, Benalaxyl, Cis-vaccenic corrosive, Levomenol, Profenofos, β-Tocopherol and β-Sitosterol, while the remainder of the mixes were comparable in both leaf and latex. Major of bioactive compounds presents Gas Chromatography-Mass Spectroscopy (GC-MS) analysis. C. gigantea is a perennial plant abundantly found in all parts of the country (India) and wild in nature. The leaves of the plant were found to contain various primary and secondary metabolites

PHARMACOLOGICAL AND ANTI CANCER ACTIVITY OF Ipomoea sepiaria METHANOLIC EXTRACT AGAINST PC-3 CELL LINE

A few conventional restorative plants contain in explored concerning their enemy of corpulence likely wellsprings of is Ipomoea sepiaria Koenig ex. Roxb. The medicine is supposed in tales game plan of prescription for various accommodating properties like, love elixir and arsenic hurting, tonic, re-establishing, diuretic, laxative, uterotonic and sterility in women and leaves is shown particularly in diabetes. Phytochemical screening of different concentrates of Ipomoea sepiaria exposed the presence and non-attendance of various phytochemicals are available in ethanol remove, further examinations were done with leaves of Ipomoea sepiaria ethanol separate. PC3 (PC-3) is a human prostate malignancy cell lines that are profoundly utilized in examining the biochemical changes prostatic disease cells. Explores on PC-3 human prostate malignancy cell lines control are required in the current many years. The anticancer action of fluid concentrate of Ipomoea sepiaria was researched by 3-(4,5-dimethylthiazol-2-yl)- 2, 5-diphenyltetrazolium (MTT) measure utilizing PC-3 cell line. The current experimentation was indicated that watery concentrate of Ipomoea sepiaria, when exposed to various focuses on PC-3 cells demonstrated IC50 cell hindrance at about 5μM for 48 hours and about 2 μM for 72 hours. The information made by this particular examination gives relevant pharmacognostic  and phytochemical data needed for proper distinctive confirmation and check of leaves of this particular  species. &nbsp

A Four-Unit-Cell Periodic Pattern of Quasiparticle States Surrounding Vortex Cores in Bi2Sr2CaCu2O8+d

Scanning tunneling microscopy is used to image the additional quasiparticle states generated by quantized vortices in the high-Tc superconductor Bi2Sr2CaCu2O8+d. They exhibit a Cu-O bond oriented 'checkerboard' pattern, with four unit cell (4a0) periodicity and a ~30 angstrom decay length. These electronic modulations may be related to the magnetic field-induced, 8a0 periodic, spin density modulations of decay length ~70 angstroms recently discovered in La1.84Sr0.16CuO4. The proposed explanation is a spin density wave localized surrounding each vortex core. General theoretical principles predict that, in the cuprates, a localized spin modulation of wavelength L should be associated with a corresponding electronic modulation of wavelength L/2, in good agreement with our observations.Comment: 10 pages, 3 figure